To tighten vehicle regulations is recently in progress specifically in Europe and the like. For example, a strength test is newly scheduled for a large cabover truck or the like in which an upper side surface of a cab 1 is hit by an impactor 2 to precedingly apply a side-surface impact as shown in FIG. 1, and then an upper surface on a roof panel 3 of the cab 1 is hit by a further impactor 2′ to apply a vertical load as shown in FIG. 2.
Specifically, the new strength test is for testing of strength of the cab 1 in overturn. In an actual overturn, precedingly the cab 1 rolls on its side to apply the side-surface impact on the upper side surface of the cab 1 and then the cab 1 further rolls into upside down (180-degree turn) to apply the vertical load on the cab 1. In the test, consideration is taken on such impacts applied in the actual overturn.
A related reference to the invention is, for example, Patent Literature 1 mentioned below.